Microsoft’s Eron Kelly has recently blogged about Azure SQL Database introduces new service tiers, where the existing Web and Business service tiers will be replaced in twelve months, as they are gradually replaced by six new service tiers, including Basic, Standard 1, Standard 2, Premium 1, Premium 2, and Premium 3. There will be differences in the “self-recovery” level and geo-replication levels across the SKUs.

Here are a couple of new acronyms for you to learn:

Database Throughput Unit (DTU): The resources powering each performance level are represented in DTUs. It combines CPU, memory, physical reads, and transaction log writes into a single unit. A performance level with 5 DTUs has five times more power than a performance level with 1 DTU. The “Database Throughput Unit” (DTU) represents database power and is meant to replace hardware specifications in the context of Azure SQL Database. 

Azure SQL Database Benchmark (ASDB): ASDB measures the actual throughput of a performance level by using a mix of database operations which occur most frequently in online transaction processing (OLTP) workloads.

Table 1 shows some relevant information about these new Azure SQL Database service tiers.

Service Tier Monthly Cost/DB Database Size Limit DTU/Database ASDB Transactions/Minute
Basic $4.99 2GB 1 DTU 58
Standard 1 $40.00 250GB 5 DTU 283
Standard 2 $200.00 250GB 25 DTU 1,470
Premium 1 $930.00 500GB 100 DTU 5,880
Premium 2 $1,860.00 500GB 200 DTU 11,520
Premium 3 $7,440.00 500GB 800 DTU 43,800

Table 1: Azure SQL Database Service Tiers

While the new service tiers are in a “preview” status, pricing will be 50% lower than what is shown in Table 1. You can read more about pricing details here. I am most interested in exploring the information disclosed in the new Azure SQL Database Service Tiers and Performance Levels, blog post, since it give us some more concrete information about what a DTU is. There is also some more detailed information about the new ASDB in the Azure SQL Database Benchmark Overview.